the oceans formed when the.............. ................. condensed when the Earth cooled.

Water vapour.

5 of 48

Green plants evolved over most of the Earth. they were quite happy in the.........atmosphere.

CO2

6 of 48

alot of the early CO2 dissolved into the oceans. The green plants also removed CO2 from the air and produced O2 by..........................

photosynthesis.

7 of 48

when plants died and were buried under layers of sediment, the carbon they had removed the air(as CO2) became 'locked up' in............................ ................. as ............................ ........................... and fossil fuels.